The major benefit of capitalism has been a rising standard of living. The major negative impact of capitalism has been a lack of regard for things other than money.
Capitalism has helped make the world richer. Capitalism promotes material progress through relentless competition. This is why all of the rich countries of the world are those that embrace capitalism.
At the same time, however, capitalism has had negative impacts. It encourages people to care about wealth above all. This has led to physically tangible problems such as environmental degradation. It has also led to more cultural or societal problems such as a lack of social ties between people.